The broad objective of this research proposal is to gain insight on the mode of action of certain in vivo Cu interactions, particularly the metabolism of copper proteins and ceruloplasmin. The research proposed is aimed towards elucidation of three basic problems: (1) "Teart disease," a copper X molybdenum X sulfate interaction; (2) metabolism and characterization of copper proteins as related to liver copper storage; biosynthesis of ceruloplasmin and superoxide dismutase in the neonatal piglet; and (3) metabolism of ceruloplasmin and ferritin in zinc toxic rats.